Changes in temperature affect microbial degradation of plastics

In order to solve the ecological problems that traditional plastics are difficult to degrade naturally, many countries are developing new plastics that use polyhydroxyalkanoates as raw materials and can be degraded by aquatic bacteria. However, Russian experts recently discovered that weather conditions such as abnormally high temperatures can greatly reduce the biodegradation rate of such plastics.

According to reports by Russian media, some bacteria can synthesize an intracellular polyester, polyhydroxyalkanoates, as a carbon source for their growth. The properties of this material are similar to those of the traditional plastic, polypropylene. The polymer plastic processed by it can be gradually degraded by several aquatic bacteria into small molecules such as carbon dioxide and water. In order to further study the degradation properties of this plastic, experts at the Institute of Biophysics of the Russian Academy of Sciences used polyhydroxyalkanoates to make thin slices and put them into nylon mesh bags, which were immersed about 1 meter below a tributary level in the Yenisei River. Then, the flakes are removed and weighed on time, and the degradation rate of the flakes is calculated.

The results showed that aquatic bacteria can degrade this slice by 1 milligram during the night, but if the temperature in the local spring rises abnormally and the temperature of the experimental water reaches 13.4 degrees Celsius, the cyanophytes in the water will generate a large number of twins, giving rise to degrading leaf bacteria. The adverse effects of the living environment caused it to reduce the rate of degradation of polyhydroxyalkanoates by 97.5%. After the winter season, the number of these degrading bacteria will drastically decrease. If the temperature is still high in the spring of next year, the degradation process of the experimental flakes will be greatly prolonged.

Experts believe that the above findings indicate that climate change and the development of certain new materials are not two separate research topics. Climate anomalies can significantly affect the results of new materials research.

Source: Shenzhen Packaging Network